<template>
  <view class="viewport">
    <!-- 推荐封面 -->
    <view class="cover">
      <image :src="bannerPicture"></image>
    </view>
    <!-- tab栏 -->
    <view class="tabs">
      <text
        class="text"
        v-for="(item, index) in recommendList"
        :key="index"
        :class="{ active: index === activeIndex }"
        @tap="changeTabs(index)"
      >
        {{ item.title }}
      </text>
    </view>
    <!-- 列表内容 -->
    <scroll-view
      scroll-y
      class="scroll-view"
      @scrolltolower="handleScrolltolower"
      v-for="(item, index) in recommendList"
      :key="index"
      v-show="activeIndex === index"
    >
      <view class="goods">
        <navigator
          hover-class="none"
          class="navigator"
          v-for="goods in item.goodsItems.items"
          :key="goods.id"
          :url="`/pages/goods/index?id=${goods.id}`"
        >
          <image class="thumb" :src="goods.picture"></image>
          <view class="name ellipsis">{{ goods.name }}</view>
          <view class="price">
            <text class="symbol">¥</text>
            <text class="number">{{ goods.price }}</text>
          </view>
        </navigator>
      </view>
      <view class="loading">正在加载...</view>
    </scroll-view>
  </view>
</template>

<script>
import { getHomeRecommend } from "@/api/home";
export default {
  data() {
    return {
      // 背景大图
      bannerPicture: "",
      // 当前显示的tab栏
      activeIndex: 0,
      // 列表数据
      recommendList: [],
    };
  },
  async onLoad({ type }) {
    // 接口地址和标题数据写死
    const urlMap = {
      1: { title: "特惠推荐", url: "/home/preference/mutli" },
      2: { title: "爆款推荐", url: "/home/inVogue/mutli" },
      3: { title: "一站买全", url: "/home/oneStop/mutli" },
      4: { title: "领券中心", url: "/home/new/mutli" }, // 后端未提供，暂用新鲜好物url
      5: { title: "新鲜好物", url: "/home/new/mutli" },
    };
    //设置一个控制是在加载的全局变量
    this.isLoading = false

    //选中项存起来
    this.currentItem = urlMap[type];
    console.log(this.currentItem);
    // 动态设置标题
    uni.setNavigationBarTitle({
      // this.currentItem是个对象，需要.title获取到标题
      title: this.currentItem.title,
    });

    //获取特惠推荐数据 首次发请求用默认的请求参数,data可以不传
    const res = await getHomeRecommend(this.currentItem.url);
    console.log("res  ----->  ", res);
    //背景大图
    this.bannerPicture = res.result.bannerPicture;
    //处理接口返回的数据成我们想要的
    this.recommendList = res.result.subTypes.map((v) => ({
      id: v.id,
      title: v.title,
      goodsItems: res.result.goodsItems[v.id],
    }));
  },
  methods: {
    changeTabs(index) {
      this.activeIndex = index;
    },
    //处理分页 滚动条触底事件
    async handleScrolltolower() {
      // 1.判断页码是否少于总页码
      // 2.page++
      // 3.重新发请求
      // 4.追加数组 和  更新页码
      // 5.节流
      // 5.1 设置1个变量isLoading = false
      // 5.2 发请求前判断是否在加载 if(!isLoading) 如果没有在加载 通过
      // 5.3 加载的时候把isLoading改为true ,加载完成把isLoading改为false

      // 选中的tab栏的id
     const id = this.recommendList[this.activeIndex].id

      let { page, pages, pageSize } =
        this.recommendList[this.activeIndex].goodsItems;
      console.log("  page,pages,pageSize----->  ", page, pages, pageSize);
      // 如果没有在加载，并且当前页小于总页数
      if (!this.isLoading && page < pages) {
        this.isLoading = true //开启加载中
        page++;
        const res = await getHomeRecommend(this.currentItem.url, {
          page,
          pageSize,
          subType: id,
        });
        //关闭加载中
        this.isLoading = false //关闭加载中
        //更新data中的页码
        // this.recommendList[this.activeIndex].goodsItems.page = res.result.goodsItems[this.recommendList[this.activeIndex].id].page
        this.recommendList[this.activeIndex].goodsItems.page =
          res.result.goodsItems[id].page;

        //更新data中的数组 追加
        this.recommendList[this.activeIndex].goodsItems.items = [...this.recommendList[this.activeIndex].goodsItems.items,...res.result.goodsItems[id].items]
      }
    },
  },
};
</script>

<style lang="scss">
page {
  height: 100%;
  background-color: #f4f4f4;
}
.viewport {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 180rpx 0 0;
  position: relative;
}
.cover {
  width: 750rpx;
  height: 225rpx;
  border-radius: 0 0 40rpx 40rpx;
  overflow: hidden;
  position: absolute;
  left: 0;
  top: 0;
}
.tabs {
  display: flex;
  justify-content: space-evenly;
  height: 100rpx;
  line-height: 90rpx;
  margin: 0 20rpx;
  font-size: 28rpx;
  border-radius: 10rpx;
  box-shadow: 0 4rpx 5rpx rgba(200, 200, 200, 0.3);
  color: #333;
  background-color: #fff;
  position: relative;
  z-index: 9;
  .text {
    margin: 0 20rpx;
    position: relative;
  }
  .active {
    &::after {
      content: "";
      width: 40rpx;
      height: 4rpx;
      transform: translate(-50%);
      background-color: #27ba9b;
      position: absolute;
      left: 50%;
      bottom: 24rpx;
    }
  }
}
.scroll-view {
  flex: 1;
  overflow: hidden;
}
.goods {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  padding: 0 20rpx 20rpx;
  .navigator {
    width: 345rpx;
    padding: 20rpx;
    margin-top: 20rpx;
    border-radius: 10rpx;
    background-color: #fff;
  }
  .thumb {
    width: 305rpx;
    height: 305rpx;
  }
  .name {
    height: 88rpx;
    font-size: 26rpx;
  }
  .price {
    line-height: 1;
    color: #cf4444;
    font-size: 30rpx;
  }
}
.goods .symbol,
.goods .decimal {
  font-size: 70%;
}
</style>
